Vacuum cleaner filter



Dec- 19, 1939- T. E. D. BILDE 2,183,737

` VACUUM CLEANER FILTER Filed Marh 5. 1957 2 Sheets-Sheet l V NTOR.

Maf/@J 'l ATTORNEY.

Dec. 19, 1939. T. 1r-ifo. BILDE 2,183,737

` I VACUUM CLEANER FILTERv l Filed March 3, 1937 ZYSheets-Sheet 2 1NVENTOR.

464." ATTORNEY.

Patented Dec. 19, 1939 VACUUM LEANEarmTaa 'rox-a Erik Daniel nude, stockholm, sweden, as-

lignor to Electrolux Corporation, Dover, Del.. a corporation of Delaware appueauon Maren 3, 1937, serial No. 128,105

In Germany March 6, 1936 3Claima.

My invention relates to vacuum cleaner filters and more particularly to an improved filter and its arrangement in combination with a vacuum cleaner unit.

One of the objects of my invention is yto pro vide a filter of comparatively small size, but having a large filtering area. In accordance with my invention, the lter cloth or other ltering material, is givenan undulated form in order to accomplish the last mentioned object. In order that the construction of the filterwill be simple the undulations are located parallel to one' side of the filter cloth, thus making possible the use of a rectangular piece oi'- material and avoiding the necessity of cutting it into odd shapes. This also eliminates waste of material.

Another object of my invention is to provide a filter which may be readily removed fromthe vacuum cleaner unit, for the purpose of cleaning or replacing it, without requiring the use of any special tool or the like.

Further objects and advantages of my invention will be apparent from the following description when considered in connection with the Vaccompanying drawings, which formpart of .this

specication and of which- Fig. 1 is a cross-sectional view of one embodiment of my invention;

Fig. 2 is a perspective view` of the filter shown in Fig. 1;

Fig. 3 is a cross-sectional view taken on the linel 3-3 of Fig. 1;

Fig. 4 is a cross-sectional view of a second embodiment of my invention;

Fig. 5 is an end view ofthe lter shown in Fig. 4, and

Fig. 6 is a side viev, partially-broken away of the filter shown in Figs. 4 and 5.

Referring more particularly to Fig. 1, reference character I designates generally the casing of a vacuum cleaner unit. Casing III includes a cylin drical portion II and end caps I2 and I3. End cap I2 is formed with a threaded inlet opening Il which is adapted to receive a hose or suction conduit I5, leading to a suction nozzle I6. A rigid tubular handle member II may be interposed between hose I and nozzle I3. Disposed within casing Ill is adust separating member I3, here shown in the form of a. bag secured to a ring I3.' Ring I9 has an outwardly extending flange which is adapted to be clamped between cap I2 and the end of cylindrical portion II, when the cap is secured in place, as by-means of spring clips 20.

'I'he opposite end of cylindrical portion II includes a ring 2l, preferably made of insulating l (ci. lss-71) material such as Bakelite", which supports a motor fan unit 22. Likewise vsecured to ring 2l is a hood member 23 formed with openings 24 therethrough. Hood member 23 is thus fixed within the casing and serves as a guard for the YI electric motor when ythe end cap 'I3 is removed.

The end cap is formed with an exhaust opening 25 which may be threaded to receive hose I5 and across which opening extend inclined vanes 28. The center vane is formed as a bushl0 ing 21 through which extends a rod 28, the outer end of'which is formed with a knurled knob 29. The opposite end of rod 23 is threaded and is adapted to engage a threaded member xed to hood member 23. Thus, rod 28 serves to secure 15 end cap'I3 in place. 'I'he end cap may be removed `by merely unscrewing the rod from member 30.

Reference character 3l designates generally my improved filter. The filter includes a base por- 20 tion 32 made of cardboard, Wood or other suitable cheap and fairly stiff material. Secured to opposite ends of base portion 32, or integral therewith, are end portions 33, the edges of which are deeply notched as is shown at 34. A piece of 25 filter cloth, or other suitable exible filtering material 35 having initially a rectangular shape, has one edge 36 secured to one side of base portion 32. The edges of lter cloth 35 which extend at right angle to edge 36 are supported 30 from end portions 33, while the other edge issecured to the opposite side of base portion 32. The filter cloth may be secured to the base and end portions by being glued thereto. The notched edges of the portions 33 result in an undulated 35 surface of the filter cloth.

The central portion of the undulated surface is formed with an opening 3'l-through which rod 23 is adapted to extend. The rod is formed with a collar 33 which serves to hold this portion of 40 the filter clothY tightly against member 30, thus preventing passage of air through the opening 3'I.

Base portion 32 is formed with a large opening 33 which is adapted to embracean annular `member secured to the'end cap I3 around the 45 exhaust opening 25. Member 40 serves to support the base member and to prevent the passage of air from within cap I3 to the opening 25 without the air having passed through the filter.

In order to prevent ,fluttering of the central portions of the filter material, which might result in the passage of dirt particles, members -42 extending through the troughs of the undulatlons ymay be provided. Members 42 are resilient and bowed downwardly at I3 so as to hold the lter 55 material taut. The resilient ends 44 of members 42 are arranged to snap over the end portions 33, thus holding the members in place. A

In operation the rotation of the motor fan unit serves to draw air inwardly through nozzle I6, hollowhandle II, and hose I5 to the inlterior of dust bag I8. As the nozzle is passed over a dusty surface, dust is entrained with this air. All but the very nest particles of dust are separated from the air stream by the dust bag I8 and are retained therein. The air and possiloly` the very finest particles of dust pass through the bag and are discharged from the motor fan unit through the openings 24 in hood 23 to the interior of cap I3. The air then is forced to pass through the filter material 35 to the space within the filter from Where it passes through opening 29 and exhaust opening 25 to the atmosphere. Due to the very large surface of the filter material resulting from its undulated shape, this material offers very little resistance to the passage of air. The nature of this material is such that it separates the very finest dust particles, as well as bacteria. It also serves to deaden the noise resulting from the operation of the motor fan unit.

In the event that it is desired to remove the filter 3| for the purpose of cleaning it or replacing it with a new one, rod 28 is rotated by means of knob 29 so as to disengage the threaded end of the rod from member 3D. End cap I3 may then be removed and the filter 3| may be removed from the end cap.

In the embodiment shown in Figs. 4 through 6, the filter consists of a pair of spaced circular discs and 5I, the outer edges of which are notched. Thesediscs may be held in spaced relation by means of spacer members 52. Filter material 53 is supported between the notched edges, which giveit an undulated surface. In this case, the lter material initially-.has a rectangular shape before being secured to the discs.

Disc 50 is provided with a small aperture 54 through which extends rod 28, while disc 5I is formed with a large aperture 55 which embraces the member 40 which is secured to the end cap.

The operation of this embodiment is substantially the same as that described in connection with the first embodiment. The air, after it is passed through openings 24 in hood 23, passes radially inwardly through the filter material Il to the interior of the iilter, from where it passes through opening 55 to the exhaust opening 2l. In this embodiment it willbe noted that the iilter is clamped-between theipap I3 and ,the hood 2l when the latter is secured in place, thus assuring that all of the air passes through the filter. The lter may be removed by unscrewing rod 2l to thereby release the end cap. After the end cap has been removed, the filter may be removed therefrom and cleaned or replaced by a new one.

While I have shown two more or less specific embodiments of my invention, it is to be understood that this has been done for purposes of illustration only and that the scope of my invention is not to be limited thereby, but is to be determined by the appended claims viewed in the light of the prior art.

What I claim is: Y

1. Ina iilter for a vacuum cleaner, a pair of Vspaced discs formed with notched edges, and

iilter material supported between said edges, whereby said material isl formed with van undulated surface one of said,discs being perforate and the other disc being imperforate.

2. In a filter for a vacuum cleaner, a first disc,

a second disc, the edges of said discs Vbeing notched, and filter material secured between said notched edges and following the contours thereof, whereby'the surface of said material is undulated, one of said discs being formed with an opening communicating with an exhaust opening of the vacuum cleaner.

43. In a filter for a vacuum cleaner, a plurality of air impervious walls, said walls extend,- ing parallel to each Vother and formed with notched edges, and filter material supported be- `tween said notched edges whereby the surface of said material is Iundulated, one of said walls being formed with an aperture communicating with an outlet opening in the vacuum cleaner.

TORD ERIK DANIEL BILDE. 

